1. Field of the Invention
The present invention relates to a microstructure, a multilayer wiring board, a semiconductor package, and a microstructure manufacturing method.
2. Description of the Related Art
A microstructure provided with a plurality of conductive paths in an insulating substrate is used as an anisotropic conductive member in various electronic components.
An anisotropic conductive member, when disposed between an electronic component, such as semiconductor device or the like, and a circuit board and then subjected to merely the application of a voltage, is able to provide electrical connection between the electronic component and the circuit board. Accordingly, such members are widely used, for example, as electrically connecting members for connection of electronic components such as semiconductor devices and the like, and as inspection connectors for functional inspections of electronic components such as semiconductor devices and the like.
In recent years, with the increasing complication of wiring of electronic components, achieving miniaturization by forming conductive paths formed of an anisotropic conductive member with a small diameter and arranging the conductive paths with a narrow pitch has been proposed.
For example, JP2008-270158A discloses “an anisotropic conductive member in which, in an insulating substrate, a plurality of conductive paths consisting of a conductive member pass through the insulating substrate in the thickness direction in a state in which the conductive paths are insulated from each other and are provided in a state in which one end of each conductive path is exposed at one surface of the insulating substrate and the other end of each conductive path is exposed at the other surface of the insulating substrate, the density of the conductive paths is 2,000,000 pieces/mm2 or more, and the insulating substrate is a structure consisting of an anodized film of an aluminum substrate having micropores (through holes)” (“Claim 1”).
In addition, JP2013-069629A discloses “an anisotropic conductive member in which, in an insulating substrate, a plurality of conductive paths consisting of a conductive member pass through the insulating substrate in the thickness direction in a state in which the conductive paths are insulated from each other and are provided in a state in which one end of each conductive path protrudes from one surface of the insulating substrate and the other end of each conductive path protrudes from the other surface of the insulating substrate, the density of the conductive paths is 2,000,000 pieces/mm2 or more, the insulating substrate is composed of an anodized film of an aluminum substrate having micropores (through holes), and a ratio (protrusion portion/through portion) between an average diameter of portions of the conductive paths protruding from the surface of the insulating layer substrate and an average diameter of portions of the conductive paths passing through the insulating layer substrate is 1.05 or greater” (“Claim 1”).